Machine-tool guard



June 22, 1948. E. J. KEARNEY ETAL 2,443,734

MACHINE TOOL GUARD Original Filed June 8, 1958 3 Sheds-Sheet 1 .INVENTORS E.J. KEARNEY, 06660560; 41/ o w. CARPENTER JR, Adm/. JBLARMITAGE & w. M. POHL.

BY 77% WW ATTORN EY 3 Sheets-Sheet 2 MACHINE TOOL GUARD' E. J. KEARNEY ETAL June 22, 1948.

Original Filed June 8, 1938 Y, fiecea eaf y QWCARPENTER JR, 4d/I/l;

J.B.ARM|TAGE & W.M. POHL.

' INVENTORS E.J. KEARNE BY flaw fl ATTORNEY June 22, 1948. 5. J. KEARNEY ETAL MACHINE TOOL GUARD 3 Sheets-Sheet 3 Original Filed June 8, 1938 0 S 6 Y R aJ E o0 W N NE 0 W -w IIKMII m E A v B B Patented June 22, 1948 s by Qtto W J Carpenter, J12, special adminr, jlioxjoin iZi .,,.end, J seph. A mi:

ealewviieow iese W enfl w l h.

- Harriden, Conn,

assignors to Kearney &

'll i-ecl'rer 'Gorporatiori, West Allis, Wis, a corv notation of Wisconsin .Qrieinal. application June, .8, 1938, Serial No.

12177112 riowz ent 5.0v8. dated Au us 944, s t-r is 5431581 .iciee r 5: Claims.

This. invention relates generally to machine tools. and more particularly to an improved guardsfor-the cutterof-a-machir e tool.

-.Thepreseht specificationconstitutes a division of applicationi'serial' N0.'21'2',704,'f1led June 8, 1938,,no w. Patent No. 2,355,082, dated AugustMS, 19.44.

Av generalobject. of this invention .istoprovide an improvedwutter guard for a=machine tool.

Another object of the invention is to provide a. hingedly mounted g-uard capable. of swinging movement upon being engaged "by a moving member.

Another object of the invention. is. to provide an adjustable.guarddisposed for selective position-ing relative; to the. various machine. members.

Another object. of the invention is to provide a machine guard especially adapted to .protect the machineoperator. and to. confineflying chips or other matter;

Anotherohject ofptheinvention isvto .provide a guard, which maybe removed readily to vfacilitate access-tattle machine whileit is being set cl enedor re aired.

e-pc rdiust hisinv ntioni a. uardfis provided which may be adapted; to. anytype of: machi toolor othermachine, wherein it is necessary-t0 pr vi e pro e ti n to. he ach ne o e e frcim ta i o e: ma hi e part and from flying chips, coolant :1iqt1ids, -ai1d other; .aterial. The guard is, coustituted hy transparent; panels pivotally suspended from a, cross rnernber that is adjustablysupported atits endsuponupstand ing post-s. By raising or. lowering the cross member, the position ofuthe guard may be .ad justed toadaptit to the-.particular-work athand. Since the guard panelsarepivotally'mounted, they. may be. positioned close t-o the work, with assurance that they will swing aside if struck. Theend postsare so mounted on the machine that. the [entire guard may be removed readily to afford-access :tothe .ma'chine elements.

The ioregping and other objects. of this inventien, which will .loe come more fully apparent from the followingdetailed description, may be achieved by means of the exemplifying, apparatus depictedin, and se iqr hin this pecifica in connect t he.fl flm y ne-drawings, in which:

Figure 1 ,is a sid .elevational .viewoi a machine toolprovided ,a guard embodying the pres entinvention;

Figure 2, is. atop plan view of the machine o Llsh wn -r l' l rnd 3, isleview partly in front elevation fi idfiliividedjand this application July 6,

,2 and partly; in vertical section, showingdetails of the-guard structure.

Referring more specifically tolpthe digawing s, Figures 1 sin-d2. thereof showrthe gener al structureof-a milling machineprovidedwith a guard constructed in accordance with the-priciplesioi this invention; and particularlyreferred'to herein, byway of example. Asthereshown, the-machine is of the continuously operating type andcomprises essentially. a bed or base 39,-having secured at its; back, an upstanding spindle-supporting col- 11:11:17 3}, which carries an adjustablyrnounted1tool spindlesg. Rotatably mounted'on the-top. ofthe bed Edi-n; front of-the. column 3!, is. a horizontally disposed circular work-supporting tablefiaa, can rying a pair of work-holding fixtures 34. and 3 5 disposedthereon in diametrically opposed relationship.

llhe two work-holdingfixtures-3,4 andvh-are supported-on the table 33, in manner to be. .movable radially thereof, by means-of- ,a. reciproeating cross slide that .is slidebly, mounted diametrically of the table; astshown in Figure 2, the fixtures being rotatably. mounted. hear, the ese ct v e dso h -s id y th s arran emerit; the work-holdingvfixtuives are movably mounted on-thetable 33; in, such mannernthat when the table is rotated, the .fixtures in turn ing with itmay he guided successively through th cutting one along. a p edetermined path- In the. particular structure shown, the, two work-holders 35,.;and 35am caused to follow a straight line path through the cutting. zone, as the tableis rotated, the fixtureseach having a compound motion, by reason of the slidineand turning movements provided ,by, its ,liqtatahle mounting ,on the, reciprocating cross slide 3?. This,..arrangement provides .for feedin Work nie s uc sivel in he same. direction, alone th s a ht n p hr ueht tt n zone, and then leading them away, withoutthenece sity of withdrawing them, past the cutter.

The. cutter suppo t ng spindle "3.2.. is a ran e to he ,adjustedreiauve to. the. work table as; both in vertical directionand transversely of the path of moveme the wor -hold ng.fixtu es an and 35 through the.cutting,. zone. Toproyidejgnthe vertical adjustment, the supporting spindle. is a i d .by e. sp nd e Z1 hi h i slidably mountedpn theoolvmn .31 ,ehahd .whs 'fifitsel'yzing. to o erate m chan sm. o .movine.t e. ead er yq lo e t olum ar; a wellknown manner. To provide for adjusting thespjildl? trensver elvei t e c t in path,. it is rotetehly m unts-Xiv by; memei. entkfri tientnri stheee ings in a quill, which is slidably mounted for aX- ial adjustment in the spindle head 42, a manually operated. mechanism 5i being provided for effecting the adjustment in a well known manner. The usual overarms 54 are slidably mounted in the upper part of the spindle head 42, in position to carry a depending arbor support 55, in which the end of an arbor 555, carrying a cutter 5'5, is rotatably supported.

In o erating the machine, the work-holding fixture, which happens to be in the forward position or loading station, may be loaded with a work piece while the table is turning slowly at feed rate. At the end of the feeding stroke, the table is automatically turned at rapid traverse rate, to cause the work piece to approach quickly to a position closely adjacent to the rotating cutter 51, the work piece being clamped automati cally as the table is turned. The rate of table movement is then automatically changed back to feed rate, in order to feed the work piece along the straight line path, through the cutting zone, in operative engagement with the cutter 57.

After the work piece has passed the cutter, the table is again automatically moved at rapid traverse rate, in the same direction, to quickly lead away the finished work piece and to bring it around to the forward position for unloading, a new Work piece in the other fixture, meanwhile, being moved simultaneously into position for feeding to the cutter. By this arrangement, the work table may be turned continuously in the same direction, alternately at rapid traverse rate and at feed rate, .with the cutter rotating to effect substantially continuous milling of successive work pieces.

The details of construction of the mechanism for effecting automatic movement of successive Work pieces past the cutter of this machine and its mode of operation are more fully set forth in the previously-mentioned parent application, which resulted in Patent No. 2,355,082.

The particular machine tool herein set forth is exemplary of apparatus with which the guard embodying the present invention may be utilized to advantage, although it is to be understood that the guard is readily adaptable to other machine tools or similar machinery.

The machine guard to which this invention is particularly directed serves to protect the machine operator from contact with the cutter and from chips, coolant liquid, or other material that may be thrown from the cutter. As utilized in connection with the milling machine herein set forth, the guard structure is mounted around the cutting zone, as shown in Figures 1 and 2. The structure includes a removable back plate 53 that cooperates with an apron attached to the spindle head 12 in closing the back of the cutting zone on the machine, one edge of the plate being slidably fitted in a groove 6! in the right side of the vertically movable head 42. With this arrangement, the head may be adjusted vertically, without disturbing the plate (iii. The other edge of the guard back plate to is slidably fitted in a slot 652 in a corner post 63, removably mounted in the right rear corner of the bed 36, as shown in Figure 2.

At the sides of the bed as, the cuttin zone is enclosed by removably mounted side plates 65 and 66, respectively, the plate 65 being slidably engaged in another slot or groove 6'! of the corner post 63 and a similar groove 68 in a for- Ward corner post or end post 59, while the plate 66 is fitted at one edge in a slot 10 (Figure 2) in the column SI and at its other edge in a slot H in another forward corner post or end post 12. The plates 6!], 65 and 66 are readily removable by sliding them upwardly in their respective retaining slots, to provide access to the cutting zone for changing cutters, making adjustments or the like.

The front of the cutting zone is guarded by means of a shield Hi, which extends across the machine between the two front corner posts 69 and 12, as shown in Figures 2 and 3. This shield or guard consists of a crossbar 16, carrying three depending guard plates or transparent panels 71, i8 and 19, preferably of non-shatterable safety glass, or the like. The ends of the crossbar it have threaded engagement with vertically disposed threaded shafts or adjusting screws 82 and 83, journelled longitudinally in the corner posts 69 and '12, respectively, the screws being operative to move the shield vertically for adjusting its position to correspond with the vertical position of the cutter 5'! and the position of the work pieces retained in the work-holding fixtures 34 and 35. In the present instance, the center panel it may be fixed to the crossbar 76, but the end panels W and F3 are preferably pivotally mounted thereon, in order that they may swing freely, in the event they should be struck by a work piece, to obviate danger of damage to the machine or injury to the operator. To provide the desired pivotal movement of each end panel, one member of a hinge 84 is attached to the crossbar it, while the panel is suspended vertically from the other member thereof.

As shown in Figure 3, each of the three panels ii, '23 and i9 is mounted in a frame member 85, in such manner that the edges of the transparent material are protected on both sides to preclude injury to them in the event of contact with the work pieces or parts of the work-holding fixtures 35 and 35. However, this structure may be varied, in that the panels may be made of other suitable material to which the movable member of the hinge dilrnay be attached, in any desired manner.

In certain machine operations, especially where a considerable amount of cutter coolant is used, the adjustable crossbar .78 may be lowered sufficiently to practically eliminate the open areas below the panels. Even though the end panels are struck by the work pieces or the work-holding fixtures, as they are rotated through the cutting zone, their pivotal mounting will permit swinging movement and thereby prevent injury to the machine or its operator.

The guard herein disclosed is readily removable from the machine, to permit setting up work and to facilitate adjustments or repairs to any of the work-retaining units or to the cutter and spindle. To this end, the corner posts 69 and i2 are each fitted in a socket at (Figure 3) in the top of the machine bed 33, in such manner that they may be removed readily, whenever it is desired to remove the front shield i5 from the machine, the entire shield being lifted as a unit, to withdraw the corner posts from their sockets. The rear corner post 63 is mounted in the same manner and may be removed from the machine bed 30 after the back plate 5G3 and the side plate 65 have been withdrawn from the slots.

Although the foregoing description and the accompanying drawings set forth the present invention as applied to the particular machine tool described herein, it is to be understood that the structure shown and described is intended to be illustrativeof an operative embodiment of the invention, and that it is contemplated that the various features may be incorporated in other machine structures, without departing from the spirit and scope of the invention, as defined in the subjoined claims.

The invention is hereby claimed as follows:

1. A guard for a machine tool, comprising spaced upstanding end posts, a threaded shaft journalled longitudinally in each of said end posts, a cross bar extending between said posts and having threaded engagement at its ends with said threaded shafts whereby said bar may be adjustably positioned vertically by turning said shafts, and a plurality of guard plates pivotally suspended from said cross bar.

2. In a machine tool, a base, a work supporting member movably mounted on said base, a cutter carrying head slidably mounted for vertical movement on said base, a guard for said machine comprising a plurality of posts upstanding from said base, a guard plate vertically disposed between one of said posts and said head and arranged for vertical sliding movement relative thereto, other guard plates disposed between others of said posts, a cross member adjustably supported at its ends upon two of said posts, and a plurality of transparent guard panels pivotally suspended from said adjustable cross member, whereby the area of cooperative action between said cutter carrying head and said work supporting member is effectively enclosed without interfering with observation or with movement of said work supporting member or of said cutter carrying head.

3. In a machine tool, a base, a column upstanding from said base, a work supporting table rotatably mounted on said base, a cutter carrying head slidably mounted for vertical movement on said column in cooperating relationship with said table, a guard structure including posts upstanding from said base at opposite sides of said table, a guard plate extending from one of said posts to said column along one side of said table, a guard plate extending from the other of said posts along the other side of said table, guard means extending from said last-mentioned guard plate to and having sliding engagement with said outter carrying head, a cross bar extending from one to the other of said posts, and a plurality of transparent guard plates pivotally suspended from said cross bar above said table, whereby the area of cooperative action between said table and said cutter carrying head is effectively enclosed without interfering with observation thereof or with movement of work pieces into or out of said area.

4. In a milling machine of the bed type having a base, a column upstanding from said base, a cutter carrying head slidably mounted for vertical movement on said column, and a work table movably mounted on said base in cooperating relationship with said head, a guard structure for confining a milling cutter carried by said head, comprising supporting columns mounted on said base at opposite sides of said table, a guard plate closure structure fitted in one of said columns at one end and having sliding engagement with said vertically slidable head at the other end, a cross bar adjustably mounted for vertical movement upon said supporting columns, and a plurality of transparent guard plates pivotally suspended from said cross bar above said table, the arrangement being such that both said cutter head and said suspended guard plates may be adjusted independently to accommodate them to a particular workpiece on said table.

5. In a milling machine, a base, a column upstanding from said base, a cutter carrying head slidably mounted for vertical movement on said column, a rotary work supporting table rotatably mounted on said base in cooperating relationship with said cutter carrying head, a guard structure for confining a milling peration by a cutter carried by said head upon a workpiece on said table, comprising end posts upstanding from said base at opposite sides of said table, a cross bar extending across said table with its ends adjustably supported by said end posts for vertical movement, a plurality of transparent guard plates pivotally suspended from said cross bar above said table, a guard plate extending from one of said end posts to said column forming a closure along one side of said table, a corner post upstanding from said base adjacent to said cutter head, a guard plate slidably fitted to said corner post and to the other of said end posts forming a closure along the other side of said table, and a guard plate slidably fitted to said corner post and to said vertically movable cutter head and forming a rear closure.

OTTO W. CARPENTER, JR. Special Administrator of the Estate of Edward J. Kearney, Deceased.

JOSEPH B. ARMITAGE. WALTER M. POI-1L.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 573,180 Gutmann Dec. 15, 1896 1,527,998 Serpico Mar. 3, 1925 1,573,146 Dreese Feb. 16, 1926 2,322,129 Hawkins June 15, 1943 

